The fall of the digital rectal exam

For almost 20 years, the value of the digital rectal exam (DRE), a long time staple of the complete examination of the trauma patient, has been questioned. Performing a rectal examination on all trauma patients is no longer advocated except for a few specific indications.

As recently as two months ago, trauma surgeon Michael McGonigal blogging at the Trauma Pro reinforced the message. Because a rectal examination is so uncomfortable for patients already traumatized and its yield is so minimal, he advocates doing it in only patients with spinal cord injury, pelvic fracture, and penetrating abdominal trauma. For a more extensive discussion of the topic, see Life in the Fastlane, an emergency medicine blog.

A systematic review and meta-analysis of the role of DRE in prostate cancer screening done by primary care physicians was just published in Annals of Family Medicine. Seven studies including 9241 patients who had both DRE and biopsy comprised the study. The authors found the sensitivity of DRE was only 0.51 and the specificity was 0.59. The positive predictive value was 0.41, and the negative predictive value was 0.64. In other words, it was similar to flipping a coin.

The quality of the included papers was low, and the heterogeneity between the studies was high. In reviewing other relevant literature, the authors found that about half of graduating students from Canadian medical schools had never performed a digital rectal examination. A previous survey of Canadian primary care physicians revealed that only half of them felt confident in their ability to feel prostatic nodules on DRE. Another study found when two urologists examined the same patient, “the interexaminer agreement among urologists was only fair.”

The paper’s conclusion was “Given the findings of our analysis and appraisal of available studies, we do not recommend routine screening for prostate cancer using DRE in primary care.”

In a 2011 BMJ editorial, Des Spence, a general practitioner in Glasgow, wrote “Rectal examination is unpleasant, invasive, and as an investigation has unknown sensitivity and specificity.” In young patients with rectal symptoms, cancer is unlikely, and in symptomatic older patients, a negative DRE would not preclude further workup. Spence raised similar concerns about the role of DRE in screening for prostate cancer or in patients with lower urinary tract symptoms.

UpToDate does not recommend DRE for prostate or colorectal cancer screening because there are no studies showing the performance of DRE reduces mortality rates for either tumor.

“Skeptical Scalpel” is a surgeon who blogs at his self-titled site, Skeptical Scalpel.